Leger, Sir Warham]. William was probably born in Ireland, but the date is uncertain. He appears to have killed a man in early life, to have taken refuge with the Earl of Tyrone, and to have followed him in his flight, only because he did not know what else to do. At Brussels he reported himself to Sir Thomas Edmonds, who mentioned the matter to Salisbury in his despatch on 4 Nov. 1607. He went from Brussels to Holland, and served in the army for at least eight years, during which he probably received the king's pardon. He was knighted on 25 April 1618, and on 3 July 1619 he had a large grant by patent of crown lands in Queen's County and Limerick, which was supplemented next year by a further grant in the former county. In 1624 his Dutch wife was made a denizen, and he had a company of foot on the Irish establishment. He was in London on 19 Feb. 1624–5 on the king's business, and, as he says, neglecting his own (Cal. State Papers). His time was not, however, wasted; for he returned to Ireland in July 1627 as lord president of Munster and a privy councillor, with a company of foot and a troop of horse (Morrin, pp. 197, 236, 270).
Soon after his appointment St. Leger was busy about the fortifications of Youghal, which proved useful later on (Youghal Council Book, p. 135). On 27 June 1628 he was sworn a freeman of Cork (Cork Council Book, p. 139). Some years later he ordered the discontinuance of football and hurling in the streets of Cork, and the corporation carried out the order (ib. p. 157). St. Leger was at Waterford in June 1630, and published an order there against the ‘excessive multitude of Irish beggars encumbering England.’ Constables were straitly charged to whip vagrants and hand them on to the next parish, until they came to some settled course of life, and shipmasters who took them on board were to be imprisoned (Youghal Council Book, p. 155). In November 1630 St. Leger claimed to have originated the scheme for the plantation of Ormond, the north part of Tipperary, which Wentworth afterwards took up, but which was never really carried out. St. Leger hoped to profit by the settlement (Lismore Papers, iii. 171; Strafford Letters, ii. 93, 97; Carte, Ormonde, i. 59).
When Wentworth went to Ireland in 1633, he was supported by St. Leger in his arbitrary measures for maintaining an army (Smith, Cork, i. 107). St. Leger attended the parliament of 1634 as member for the county of Cork, his position as lord president of Munster in the opening procession being immediately below the peers (Strafford Letters, i. 283). In the privy council he rather favoured delay in asking the House of Commons for money, on the ground that ‘the protestants not being well prepared, many of them might be against granting the supply, and so, joining with the popish party, might foil the business’ (ib. p. 277). Of his government in Munster there are not materials for a detailed account; but Strafford, on his trial, called him a ‘very noble and just man’ (Lismore Papers, iv. 179), from which it may be inferred that he generally supported the government; and the fact that he was not always on the best terms with Lord Cork points to the same conclusion (ib. p. 217). In 1637, when the president was engaged in litigation with Lord Antrim, Wentworth took St. Leger's part, both on the merits and because, as he wrote from Limerick, ‘the president carried himself so round and affectionately in his majesty's service that he passing well deserved the gracious regard and favour of the crown’ (Strafford Letters, ii. 97).
In April 1638 St. Leger attended the meeting of the privy council at which the chancellor, Adam Loftus, first viscount Loftus of Ely [q. v.], was unanimously suspended until the king's pleasure should be known (ib. p. 161). He sat again for the county of Cork in the parliament of 1639, and in the same year he had a confirmation of his lands under the commission of grace, and Doneraile was erected into a manor (ib. ii. 394–8; Lodge, p. 112). He took a leading part in levying and drilling the army of eight thousand foot and a thousand horse which Wentworth raised for the invasion of Great Britain, and in July 1640 he was in command at Carrickfergus. He kept strict discipline, and after a few weeks pronounced the army fit for service (Strafford Letters, ii. 403; Carte, i. 99). After the dismissal of this ill-starred host in the spring of 1641, he was active in trying to get the soldiers out of Ireland and into the service of foreign princes (Confederation and War, i. 217–44). After Wandesford's death in November 1640, Strafford advised the king to make Ormonde, Dillon, or St. Leger deputy. Had Charles chosen either the first or the third, his fate might have been different.
St. Leger was at Doneraile when the great Irish rebellion broke out on 23 Oct. 1641. The army which he had helped to raise had been disbanded, and the discharged soldiers were ready fuel for the flames. The frightened lords justices had only the old standing force to rely on, and they withdrew all the garrison of Munster to guard Dublin.